Delta beast rears its head

The U.S. Department of
Interior may be ready to resurrect the Yuma Desalting
Plant

The Southwest’s voracious demand for water
has already decimated the Colorado River Delta, turning millions of
acres of jungle-like wilderness in northern Mexico into sterile
salt flats. During dry years, the river — once mighty enough
to carve the Grand Canyon — peters out before it reaches the
Gulf of California.

And now, the little habitat still
remaining in the delta may disappear, as the U.S. tries to squeeze
more water out of a river system gripped by record drought (HCN,
7/3/00: A river resurrected). To send more water to Sunbelt cities
and Southwestern farms, the U.S. is planning to restart its Yuma
Desalting Plant.

Each year, the U.S. is required to send
Mexico about 10 percent of the Colorado’s average flow
— about 500 billion gallons a year — which is mostly
used by farms south of the border. But the water needs to have no
more than a certain percentage of salt, and the runoff from U.S.
farms into the Colorado is extremely salty. So in 1975, the Bureau
of Reclamation began to build the Yuma Desalting Plant.

Wet years in the 1990s meant that the U.S. didn’t need to use
the desalter, however, and the $222 million plant — which
critics derided as a classic federal boondoggle — has been
stuck in mothballs since its completion in 1992 (HCN, 2/21/94:
Draining the budget to desalt the Colorado).

Now, the U.S.
Department of the Interior is looking to bring the plant back
online. And once it’s running, the plant will pour its
poisonous saline dregs into the Sonoran Desert’s largest
wetland, the 12,000-acre Cienega de Santa
Clara.

“It’s caught some of us a
little off-guard, because all along we’ve assumed it was a
white elephant that would never come online,” says Steve
Cornelius, director of the Sonoran Desert Ecoregion Program of the
Sonoran Institute in Tucson.

“Milk and
honey wilderness”

The plant would use reverse
osmosis to treat brackish water flowing off cropland in
southwestern Arizona’s Wellton-Mohawk farming district,
returning the “desalted” water to the Colorado for use
downstream in Mexico. The “reject stream” of toxic
brine would be sent through a parallel canal to Mexico, and then
dumped in the cienega.

The cienega has been receiving the
runoff from the Wellton-Mohawk fields. Nowhere near as salty as the
concentrated brine that the desalting plant would pump out, the
runoff has allowed the continued blossoming of the cienega in a
dusty floodplain that is otherwise cracked like sunbaked skin and
coated with a frosting of salt.

The cienega still offers a
glimpse of the “milk and honey wilderness” that Aldo
Leopold toured by canoe with his brother in 1922, roasting quail
over mesquite fires and climbing cottonwoods to scout the
river’s path. “The river was nowhere and everywhere,
for he could not decide which of a hundred green lagoons offered
the most pleasant and least speedy path to the Gulf,” Leopold
wrote. “So he traveled them all, and so did we.” In the
days before Hoover Dam, which was completed in 1936, Leopold
recorded clouds of waterfowl, bobcats fishing for mullet, and
families of raccoons munching on water beetles.

Declared a
biosphere reserve by Mexico in 1993, the cienega provides habitat
for 280 species of birds, including the largest-known population of
endangered Yuma clapper rails. The endangered desert pupfish lives
in its olive waters. Local residents have developed a fledgling
ecotourism industry around the cienega, renting canoes so visitors
can paddle among the hissing reeds.

Changing
course

Because the U.S. doesn’t receive credit for
the 35 billion gallons of brackish runoff it sends to the cienega
every year, it has to draw an equal amount of freshwater from Lake
Mead and deliver it to Mexico. Now, with reservoirs like Mead
“dropping at a record pace,” Interior Secretary Gale
Norton says the U.S. must change course. That may mean restarting
the desalting plant.

If that happens, the cienega will get
only a third as much water — and that water will be three
times as salty, according to the Interior Department’s own
proposal, which was approved by the House of Representatives in
July. In a letter to Congress, Norton acknowledged that restarting
the Yuma plant “would be met with substantial
controversy” because it “may degrade” the
cienega’s ecology.

That’s an understatement,
according to Ed Glenn, a scientist with the University of
Arizona’s Environmental Research Lab who has studied the area
since 1991. He says he’s already worked on several federally
sponsored studies that clearly show the cienega would be ravaged by
the desalter. “That water would not meet any kind of
standards for discharge in the U.S.,” Glenn says. The
cienega’s vegetation would disappear: “It would become
a repository for selenium-laden, poisonous water.”

Secretary Norton has suggested moving forward on two fronts:
preparing to fire up the Yuma plant while looking for new sources
of water for the cienega, such as farmers’ water rights. But
Assistant Interior Secretary Bennett Raley, considered the Bush
administration’s point man on Western water issues, says no
decision has been made on the Yuma plant. Mexico has yet to be
officially notified about the plans, and will certainly demand an
environmental impact statement and mitigation, says José
Campoy, manager of the national preserve that includes the
cienega.

Interior acknowledges that the plant might
require expensive upgrades, and cost $26 million to $34 million to
run each year. But those numbers are way off, says Lisa Force,
program director of Living Rivers in Scottsdale, because the agency
has underestimated the cost of operating the plant and
overestimated the price of alternatives.

“At a time
when federal deficits are skyrocketing, it’s unbelievable
that Congress would consider throwing away taxpayers’ dollars
to retool this plant,” she says.

The
author is the environment writer at the Arizona Daily Star in
Tucson.